What’s Vulnerable › Vulnerabilities

CVE-2026-59998

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-08 · updated 2026-10-25
• Weakness: CWE-573

Description

sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.

Affected products

• OpenSSH: before 10.4 — fixed in 10.4

How to fix

Upgrade to a fixed version: OpenSSH 10.4. Check the vendor advisory for mitigations.

References

• https://marc.info/?l=openssh-unix-dev&m=178333966933090&w=2
• https://www.openssh.org/releasenotes.html#10.4p1
• https://www.openwall.com/lists/oss-security/2026/07/06/5

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